Economizer for water-tube boilers



Jul 3,1926; 1,676,126

H. E. YARROW ECONOMIZER FOR WATER TUBE BOILERS Filed May 2, 1925 fizvenzar' JY fi aroldlfl arrow Patented July 3, 1928.

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*EooNoMrz nn non WATER-TUBE BoInEns.

Application filed May 2, 1925, Serial No. 27,546, and in Great Britain November 7, 1924.

This invention relates to economizers'or feed water heaters for .water tube boilers and consists in an improved arrangement and construction of apparatus of this class which facilitates the removal either intermeet the conditions of working at the very high pressures which havebecome common in modern boilers. The invention, however,

is not limited to the use of steel tubes in the economizer, as any other suitable metal or alloy may be substituted therefor.

According to the present invention the economized is so disposed with respect to I the other elements of the boiler as to provide accommodation underneath it for a. soot hopper or dust collector to receive the soot or dust deposited from the furnace gases as i on their velocity decreases, and this hopper is preferably provided with one or more screw conveyors by means of which the accumulated dust may be removed intermittently or continuously through one or more discharge openings provided in the hopper.

In the preferred arrangement the economizer tubes are disposed horizontally above the steam drum of the boiler and extend transversely thereof, being expanded or welded into pressed or cast steel headers extending at either side of the furnace parallel with the steam and water drum, the soot hopper being disposed below the central part of the economize'r-parallel with and im mediately above the steam drum.

The invention is illustrated inthe accompanying drawings, wherein Fig. 1 is a transverse section of a Yarrow type land boiler adapted for burning pulverized fuel, and

V Fig. 2 is a view showing a modified arrange ment of the economizer embodied in the boiler of Fig. 1. 1

In the drawings A represents the steam drum; B, B the water drums; G, C the generating tubes and D the superheater; E is the combustion space and F the pulverized fuel burner.

After traversing the generator and superheater tubes the furnace gases are ledby the fines G at either side of the boilervcasing to the economizer, and after traversing the tubesH thereof they pass upwards to a central flue J leading to the funnel or to an air heater. Tubes H are expanded or welded into the circular drums K which-may be subdivided, two headers being shown at each end of the economizer. In this case N is the feed inlet header and the feed water from N traverses the upper tubes H of the economizer which tubes at their other end are connected by header O'with the intermediate tubes. H through which the feed water returns from header 0 to a header P at the other end connecting the intermediate tubesgH with the lower tubes H through which the feed water passes to the outlet header Q.

Centrally situated below the economizer and extending longitudinally parallel with the steam drum A is a soot hopper R into which the dust and soot from the furnace gases falls as the velocity-of the gases decreases on their passage amongst the tubes of the economizer. The accumulated soot may be removed from. the hopper R through an end opening S either by means of a rake or a continuously operating screw conveyor.

removing the accumulated soot from said 7 collector. v

2. An economizer for water tube boilers wherein a. steam drum is enclosed within a casing, comprising headers arranged above and on opposite, sides of the steam drum, horizontal water tubes extending between and having their ends connected to said headers, a soot collector extending under said tubes and above the steam drum and having means to permit the removal of soot accumulated therein, fiues disposed on oppo- 5 site sides of the soot collector for directing the furnace gases to the opposite ends of said tubes and between the latter, and an up-ta-ke above and between said headers for the escape of furnace gases after their passage between said tubes. 10

In testimony whereof I have signed my name to this specification.

HAROLD EDGAR YARROW. 

